Automated trading exchange system having integrated quote risk monitoring and integrated quote modification services

ABSTRACT

An automated trading exchange having integrated quote risk monitoring and quote modification services. An apparatus is implemented using at least one computer, having memory, and a processor. The computer is configured to receive orders and quotes, wherein specified ones of the quotes are contained in a quote group, and have associated trading parameters such as a risk threshold. Not all received quotes are required to have trading parameters as described herein. Preferably, the quote group contains all the quotes, or a subset of quotes, belonging to an individual market-maker for a given class of options contracts, or possibly the quotes of two or more market-makers that have identified themselves as belonging to a group for the purposes of risk monitoring and quote modification. The computer typically generates a trade by matching the received orders and quotes to previously received orders and quotes, and otherwise stores each of the received orders and quotes if a trade is not generated. The computer then determines whether a quote within the quote group has been filled as a result of the generated trade, and if so, determines a risk level and an aggregate risk level associated with said trade. The computer then compares the aggregate risk level with the market-maker&#39;s risk threshold, and if the threshold is exceeded, automatically modifies at least one of the remaining quotes in the quote group. The computer may also automatically regenerate quotes that have been filled.

A. FIELD OF THE INVENTION

The present invention relates to financial trading systems. Morespecifically, it is directed to a method and device for market-makerrisk management through automatic quote risk monitoring and quotemodification in an automated trading system.

B. DESCRIPTION OF THE RELATED ART

1. Option Trading

Option contracts are traded publicly on many exchanges throughout theworld. These securities, referred to generally as “options,” conveycertain rights to buy or sell an underlying stock, commodity, or othersecurity at a fixed price for a specific period of time—until expirationfor an American-style option or at expiration for a European-styleoption. All option contracts that trade on U.S. securities exchanges areissued, guaranteed and cleared by the Options Clearing Corporation(OCC). OCC is a registered clearing corporation with the SEC.

The potential loss to the buyer of an option can be no greater than theinitial premium paid for the contract, regardless of the performance ofthe underlying stock. This allows an investor to control the amount ofrisk assumed. On the contrary, the seller of the option, in return forthe premium received from the buyer, assumes the risk of being assignedthe obligation to buy or sell the underlying security if the contract isexercised. Therefore, writing options can lead to large potentialexposure.

Further background information may be obtained from the book “OPTIONS,Special Concepts and Trading Strategies,” The Options Institute, TheEducational Division of the Chicago Board Options Exchange, SecondEdition, McGraw Hill (1995), the contents of which are incorporatedherein by reference.

2. Open Outcry Trading and Automated Exchanges

Many trading systems utilize what is known as an open outcry method oftrading. In the open outcry system, market-makers are required to make atwo-sided market by providing a bid and offer quote in all optionseries. The market-makers typically communicate verbally or visuallywith contra traders indicating their willingness to buy and sell variousquantities of securities. Because the market-makers have personalcontrol over the types and number of contracts traded, they can adjusttheir trading strategies as their positions change. In this way, themarket-makers can manage their exposure, or risk, associated with theirholdings by adjusting their quotes to favor trades that would tend tohedge away unwanted exposure.

In an automated trading environment, a certain amount of control is lostwhen a market-maker has issued quotes in a large number of optionseries. The quotes are typically recorded in the automated andcomputer-based trading system, and matched up automatically with ordersthat enter the system electronically. With the proliferation of computertrading systems and increased communication speeds, the rate at whichtrades may be executed by an automated system far surpass the rate oftrades that occur in an open outcry system. The speeds are such that therapidity of trades may exceed the market-maker's ability to adapt his orher position. Specifically, one disadvantage of automated tradingsystems is that a number of automatic trades may occur within a veryshort time that result in an unacceptable risk being assumed by amarket-maker. That is, the trades may occur so rapidly that themarket-maker is unable to withdraw or modify his quotes in a timelymanner.

There exist software tools that can analyze stock and option portfoliosin close to real time. Market data is provided to the software analysistools and used to evaluate the risk associated with stock and optionportfolios. In addition, the tools may provide recommendations fortrades and quotes and automated submission of those trades and quotes.However, even if a market-maker utilizes such a computer-implementedautomated position analysis tool to revise or cancel quotes, thesoftware tools may be unable to act in time given the speed at which anautomated trading exchange system is capable of executing incomingorders. In particular, one aspect of existing exchange systems is thattransactions are received and processed in the order received. Thus,even if a market-maker responds immediately using an automated softwaretool, the exchange may have a message queue containing additional ordersthat will be processed before the exchange system receives and processesthe market-maker's quote cancellation request.

The result is that a market-maker who is willing to take on apredetermined level of risk must limit the number of quotes or the depth(quantity) of each quote to ensure that rapid trades do not result in anunacceptable aggregate risk, rather than issuing quotes having greaterdepth and breadth (where the filling of a single quote might reach themarket-maker's risk limit). Thus, a market-maker's limited control overrisk management may have the undesirable effect of hindering theliquidity of the market.

It would therefore be desirable to have a trading exchange system andmethod for automatically canceling, regenerating, or modifying quotesunder certain trading conditions.

SUMMARY OF THE INVENTION

A method and apparatus for an automated trading exchange havingintegrated quote risk monitoring and quote modification services isprovided. In accordance with a first aspect of the invention, anapparatus is implemented using at least one computer, having memory, aprocessor, and a communication port. The computer is configured toreceive orders and quotes, wherein specified ones of the quotes arecontained in a quote group, and have associated trading parameters suchas a risk threshold. Note that not all received quotes are required tohave trading parameters as described herein. Preferably, the quote groupcontains all the quotes belonging to an individual market-maker for agiven class of options contracts, or possibly the quotes of two or moremarket-makers that have identified themselves as belonging to a groupfor the purposes of risk monitoring and quote modification. The computertypically generates a trade by matching the received orders and quotesto previously received orders and quotes, and otherwise stores each ofthe received orders and quotes if a trade is not generated. The computerthen determines whether a quote within the quote group has been filledas a result of the generated trade, and if so, determines a risk leveland an aggregate risk level associated with said trade. The computerthen compares the aggregate risk level with the market-maker's riskthreshold, and if the threshold is exceeded, automatically modifies atleast one of the remaining quotes in the quote group. The computer mayalso automatically regenerate quotes, that is, automatically issue newquotes when trades have occurred against previous quotes.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, features and advantages of the present invention will bemore readily appreciated upon reference to the following disclosure whenconsidered in conjunction with the accompanying drawings, in which:

FIG. 1 depicts a preferred embodiment of the quote modification tradingsystem;

FIGS. 2A, 2B, 2C, and 2D show the interconnection of various softwaremodules associated with the quote risk monitoring and modificationtrading system;

FIG. 3 shows a sequence diagram of a preferred embodiment of the quotemodification system; and

FIG. 4 shows a flowchart depicting the method of modifying quotes.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENT(S)

With reference to FIG. 1, a preferred embodiment of the system 100utilized for trading and quote modification is described. The system 100(also referred to herein as a screen-based trading system, or SBTsystem) includes a plurality of computers, which may be one or moreworkstations, servers, mainframes, or other computer hardware platformsthat provide sufficient resources to meet the desired trading volume anddesired transaction-processing rate. In the preferred embodiment shownin FIG. 1, the system includes a number of computer clusters such ascluster 102 (although only one is depicted in FIG. 1), where eachcluster 102 handles trading for a number of securities, such as one ormore classes of options. In the preferred embodiment, each cluster 102is made up of two servers 104, 106. The servers 104, 106 are preferablymultiprocessor SUN 4500 servers available from SUN Microsystems of PaloAlto, Calif. SUN Enterprise™ servers or Starfire™ servers are apreferable alternative.

The servers 104 and 106 in cluster 102 communicate with a plurality ofclient servers 110, 112 that are typically located at remote locations,such as at a brokerage house, but may also be located in the samefacility as the clusters 102. Network 108 facilitates communicationbetween the clusters 102 and the client servers 110, 112. The network108 is preferably a private LAN/WAN configuration, but a public networkmay be utilized, provided sufficient redundancies and message securityare provided. Two such client servers 110, 112 are shown in FIG. 1. Eachclient server 110, 112 may be provided with a predetermined messagethroughput rate into network 108, where the throughput rate may be amaximum rate determined by various parameters, including the volume oforders sent by the client server 110, 112, the volume of quotes sent bythe client server 110, 112, the number of option series for which quotesare provided, communication/connection fees paid by the brokerage houseor other entity utilizing the client server 110, 112, the overallcapacity of the trading system 100, etc. The client servers 110, 112preferably communicate with other elements of the automated exchangesystem using a client application server module 210, as furtherdescribed below, running on client servers 110, 112.

Each client server 110, 112 is capable of serving a number of clients,shown as terminals 114, 116, 118, 120, 122, and 124 in FIG. 1. Theclient terminals 114-124 may be “dumb” terminals; stand alone computingdevices (PCs or workstations), or even portable wireless terminals. Theclient servers 110, 112 may communicate with the client terminals114-124 using a proprietary protocol or one of many standard publicdomain protocols. The client servers 110, 112 may include a web serveror connect to a separate web server for processing tcp/ip, http, html,java, and the like, and provide access to client terminals 114-124 overthe Internet in addition to (or as an alternative to) private LAN/WAN orVirtual Private Network access. For embodiments that include awebserver, the web server preferably utilizes common gateway interfacescripts (cgi) to interface with the client application server 210. Inaddition to cgi scripts, or as an alternative to cgi, other web serverinterfaces and server extensions may be utilized to providecommunication between the web server and the application server 210. Theclient servers 110, 112 communicate with the users of terminals 114-124by way of secure Internet communication protocols or by private LAN/WANor VPN communication links. Thus the client terminals 114-124 may rundedicated proprietary software to communicate with the client server110, 112, or may interface with client servers 110, 112 via a standardweb browser. The web browser may operate using built-in java scripts, ormay also include specialized browser modules that are provided to theclient terminals.

The automated exchange system 100 is comprised of the following fivelogical software modules: Presentation Services Graphical User Interface(GUI) 130 (FIG. 2A); Application Services 210 (Client ApplicationServer, Gateway) (FIG. 2A); Business Services 132 (FIG. 2B); ExternalIntegration Services 133 (FIG. 2C); and, Infrastructure Services 134(FIG. 2D).

With reference to FIG. 2A, the Presentation Services GUI module 130 isconstituted by applications that interact with the exchange system 100via the Member Interface (MI) API 135. There are two types of clientapplications, those that provide a GUI to allow user interaction withthe system directly and applications that automate trading functions.

An SBT (screen-based trading) GUI module 131 is responsible fordisplaying the contents of a particular model to the screen and updatingthe display if the model's contents change. This module 131 containsseveral GUI applications, one for each of the major classes of humanactors that use the system 100: traders, market-makers, clearing firmbrokers, and system operators. The Trader GUI is used by regulartraders. It consists of several GUI's for displaying and enteringorders, and market data. The Market-Maker GUI is an extension of theTrader GUI and is used by market-makers. It consists of several GUI'sfor displaying and entering orders, quotes, and market data. TheClearing Firm Broker GUI is an extension of the Trader GUI and used byclearing firm brokers. It consists of several GUI's for forcing thelogout of a market-maker and for setting a maximum order quantity forthe quotes and orders of the clearing firm's market-makers. The systemoperation GUI is used by system operators and help desk operators. Theautoquote system 161 runs on the market-maker's work station and is usedby the market-maker to generate quotes for various option series.

The Application Services module 210 contains subordinate modules thatforward requests initiated by human or automated actors, to be executedby the appropriate Business Services module(s) 132. These applicationssubmit requests to Business Services components 132, notify clients ofbusiness events, and maintain user-specific views of information in theBusiness Services 132. This module also encompasses a Member Interface(MI) API 135 that provides a single entry point to the system exposingthe applications in the Application Services Module 210 (i.e., Trader,Market-Maker). In addition, the Application Services Module 210maintains instantaneously updated views that reflect the prevailingstate of each actor's information in the Business Services module 132.

The Trader Application module 136 has the following specificresponsibilities: submit, cancel, update, and cancel/replace orders;submit requests for quotes; present the current status of the trader'sorders; present fill and cancel reports; present Market Best Bids andOffers for selected products; set the trader's defaults and preferences;present Book Depths for selected products; and, present underlyingquotes/last sales and news alerts.

The Market-Maker module 137 inherits the Trader App module's 136responsibilities and adds the following: submit and modify market-makerquotes; present requests for quotes; set the market-maker's defaults andparameters; set autoquote parameters; submit autoquotes.

The Clearing Firm Broker module 138 inherits the Trader App module's 136responsibilities and adds the following: assume control of a trader'sprivileges. A Clearing Firm Broker can force the logout of amarket-maker; set a maximum order quantity for quotes and orders of theclearing firm's market-makers.

The BackOffice application 139 is responsible for reporting order statusinformation. This can include fill reports, cancel reports and new ordernotifications. The Operations application 140 has the followingresponsibilities: start and shutdown the SBT system; start and stoptrading of a product; change the status of a product's market (pre-open,open, close, halt, etc.); present logged system events; maintainSBT-specific trader information; maintain SBT-specific productinformation; maintain trading parameters (quote width, minimummarket-maker order default size, required percent of responses to arequest for quote (RFQ), maximum response time to an RFQ, etc).

The functionality of the Trader 136, Market-Maker 137, Clearing FirmBroker 138, and Back Office 139 modules is exposed by a facade, theMember Interface (MI) Application Programming Interface (API) 135. TheMember Interface 135 exposes different subsets of functionalitydepending on the user that logged on to the system. The intention behindsharing a common API among the different trader classes is to allowworkstations to service all of them. Separate API's may alternatively beused for the different user classes.

The Member Interface API 135 supports both SBT client applications andexternal applications owned by members. Members use the Member InterfaceAPI to link their existing computer systems to the exchange system 100,to submit orders electronically and to automate trading. Likewise,market-makers use the API to submit autoquotes employing theirproprietary systems, instead of the default autoquote application 161provided by SBT.

The following system functions are preferably accessible through theAPI: session logon and logoff; market state inquiry and changenotification; connection status inquiry and change notification; orderentry, cancellation, and replacement; quote entry, cancellation, andreplacement; RFQ notification; order status inquiry and fillnotification; subscription to product markets; best market quotesnotification; book “depth” inquire and change notification.

Referring now to FIG. 2B, the Business Services module 132 contains thecore functionality of the automated exchange system 100. It includescomponents that correspond to the key business object model entities ofthe automated trading system such as members, orders, books, products,quotes, et cetera. In addition, it includes components to administer andoperate the system 100.

The Order Handling Service module 220 maintains the current state of allorders persistently. Specific operations may be exposed directly byOrder objects 141, bypassing the Order Handling Service 220. Logically,Orders are components of this module. Specifically, the Order HandingService 220 and Order components are responsible for: receiving andstoring incoming orders (from SBT clients or TPF 156 (FIG. 2C));forwarding incoming orders to the Broker module for execution; receivingorder state change notifications from the Broker and Order Book modulesand updating stored orders with this information (the functionality isprovided by exposing Orders, allowing the Broker and Order Bookcomponents to directly update the orders); sending fill reports tooriginating traders upon receiving fill notifications from the Brokerand Order Book modules; receiving order cancellation requests andforwarding them to the Broker and Order Book modules (upon confirmationof a cancellation, notifying the originating trader of the result of therequest and updating the stored state of the order); and receiving ordercancellation/replacement requests and forwarding them to the Broker andOrder Book modules (upon confirmation of the cancellation/replacement,notifying the originating trader of the result of the request andupdating the stored state of the order).

The Broker Service module 230 is responsible for executing the followingtypes of orders: limit, market, all or none, fill or kill, immediate orcancel, stop, stop limit, and spread. Upon trade execution, the BrokerService 230 is responsible for notifying the Trade Service module 143 ofall the orders matched (all parties to the trade) in the trade. It isalso responsible for notifying the Order Handling Service (i.e. Orders)220 and Market-Maker Quote Service (i.e. Quotes) 240 of the fills.

The responsibilities of the Order Book Service module 142 are: cooperatewith the Broker Service 230 in calculating the opening price during aproduct's pre-opening period; acknowledge that an order was accepted bypublishing an event consumed by the Trader application 136 whichoriginated the order; cancel and cancel/replace resting orders; uponchanges to the top of the book, publish the new Book Best Bid Offer(BBBO) and last sale.

The responsibilities of the Trade Service module 143 are: receive tradenotifications from the Broker Service 230; format trade reports; storetrade reports; and forward trade reports to trade match (via TPF 156).

The Market-Maker (MM) Quote Service module 240 is responsible for:receiving requests for quotes (RFQs) from traders; submitting RFQs tomarket-makers assigned to the product for which the quote was requested(by publishing in the RFQ event channel); receiving and loggingmarket-maker responses to RFQs (market-maker quotes); upon receiving amarket-maker quote, saving it persistently and submitting them to theBroker Service module 230 for execution; sending fill reports tooriginating market-makers upon receiving fill notifications from theBroker and Order Book modules; canceling or updating a Market-Makerquote upon receiving a request from the originating market-maker bysubmitting the request to the Broker/Order Book; canceling or updatingor regenerating Market-Maker quotes upon receiving a fill report; uponinquiry, providing the history of the quotes submitted by amarket-maker.

The Product Service module 144 maintains all product-relatedinformation. In order to perform its responsibilities, the ProductService module 144 downloads, and preferably caches, product informationfrom TPF 156 and TIPS 157. The User Service module 260 maintains alluser-related information, both specific to SBT and contained in theMembership System. It provides a unified interface to SBT componentsaccessing user information, hiding the actual location of the maintaineddata, thus simplifying client logic.

The User Service module 260 maintains the information of traders,market-makers, clearing firm brokers, operators, help desk personnel,back-office personnel. In one embodiment, the data is cached forperformance reasons and the data is synchronized from the TPF 156source.

The Trading Session Service module 145 maintains all business day andtrading session-related information and manages the different states ofa trading session, e.g. open, closed, and halted. Products that areprocessed/traded in each trading session are also kept at this service.In order to perform these responsibilities, the Product Service module144 downloads trading session and product information from TPF 156, aswell as monitor events that affect products traded within a session.

The Product State Service 146 is responsible for coordinating productstate changes for all products, e.g. pre-opening, opening, trading,halting, closing, and post-closing. It works closely with the BrokerService 230 to insure that state changes occur in a timely fashion. Theservice 146 monitors events that affect products traded, such asmonitoring the underlying market to detect when the primary exchangeopens, closes or halts trading a product. The Product ConfigurationService 147 is responsible for providing the location of where a productis processed/traded. This information is primarily used to routeproduct-specific requests (e.g. orders) for processing. The Order StatusService 148 provides subscription and notification services related toorders (i.e., fill reports, cancel reports, order accepted by book,etc.).

The Quote Status Service module 149 provides subscription andnotification services related to quotes (i.e. fill reports, deletionreports, etc.) The service 149 preferably replaces the use of eventchannels for quote status reporting, providing a more secure mechanismfor status delivery. The Market Data Service 150 maintains a currentsnapshot of market data, in addition to publishing market summary data.The module also provides an interface to clients to query historicalmarket data.

The Best Quote module 151 is responsible for calculating the market best(aggregate quantities of buy and sell orders at the best price) for eachproduct and sending them to TPF 156 (which in turn forwards them to theOptions Price Reporting Authority) for public dissemination. Inaddition, it is responsible for calculating and disseminating theNational Best Bid Offer (NBBO). In order to provide this information,the Best Quote module 151 subscribes to the event channel referred toherein as the Best of the Rest channel to obtain the current best quotefrom competing exchanges. The Best Quote module 151 then determines thesource of the NBBO, whether it is from the present exchange or acompetitor, and publishes the results to the Best Quote event channel,of which the TPF Adapter 152 is a subscriber.

Referring now to FIG. 2C, the External Integration Services module 133includes adapters 152, 153, 154, and 155, that map the interactionparadigms of external systems to the ones in the system 100architecture. The adapter modules “adapt” (or “wrap”) the native legacyinterfaces to interfaces appropriate in the SBT environment. The TPF(Transaction Processing Facility) module 152 contains the adapter toallow SBT and TPF 156 to interact. TPF data is received, remoduled, andbroadcast/delivered to the appropriate components within SBT.Conversely, SBT data is received, either through direct invocation orevent consumption, remoduled, and sent to TPF 156 using its nativeinterface.

The Membership Adapter 154 translates requests for member informationreceived from SBT components into requests to the Membership System 159and returns the results after reformatting.

The TIPS Adapter 155 subscribes to TIPS 157 to receive the externalmarket data needed in the SBT environment, including underlying marketdata and the Best of the Rest of options listed in SBT. The EventsService (FIG. 2D) notifies the TIPS Adapter 155 of consumersubscriptions so that it can propagate these subscriptions back to TIPS157. Once subscribed, the TIPS Adapter 155 reformats the market datareceived from TIPS 157 and publishes it for consumption by SBTcomponents. Another responsibility of this adapter 155 is to publishunderlying product state events when external markets change theirstates, for instance when they open, halt, close, etc.

The Trade Match Adapter 153 receives SBT data and forwards it to TM 158.The TM Adapter 153 handles the following data flows: Trade Report (SBTto TM)—SBT reports all the parties to a trade to TM 158.

Referring now to FIG. 2D, the Infrastructure Services module 134contains commercial “off-the-shelf” software and extended infrastructureservices that provide enterprise-wide support to various other externalsystems. One mechanism by which the SBT system components interact witheach other is by supplying and consuming events, implemented as apublish/subscribe pattern. The following list provides a briefdescription of the event flows/notification services (messagingservices) shown in FIG. 2D.

RFQ—the Market-maker (MM) Quote Service supplies RFQ events consumed bythe Market-Maker Application.

BBBO—the Order Book supplies Book Best Bid Offer (BBBO) events consumedby the Best Quote Service.

NBBO—the Best Quote Service supplies National Best Bid Offer (NBBO)events consumed by the Trader Application, and Market Data Service.

Current Market—the Best Quote Service supplies Current Market Bestevents, containing a product's best quote, consumed by the Market DataService and Trader Application. The best quote indicates if the exchangehas the best quote.

Best of the Rest—the TIPS Adapter component supplies best-of-the-restevents consumed by the Best Quote Service.

Last Sale—the Trade Service supplies last sale events consumed by theMarket Data Service 150 and TPF Adapter 152.

Last Sale Summary—the Market Data Service 150 component supplies lastsale summary events consumed by the Trader application.

Logging—the Logging Service Proxy component supplies Log Service eventsconsumed by the Log Service component.

System Management—the Foundation Framework supplies System Managementevents consumed by the System Management component.

Instrumentation—the Instrumentation Service component suppliesInstrumentation events consumed by both the System Management componentand the Log Service component.

Underlying Ticker—the TIPS Adapter supplies Underlying ticker events(prices, quotes, last sales, news alerts) consumed by the TraderApplication and the Product Service.

Underlying Recap—the TIPS Adapter supplies Underlying summary events(high and low prices, volume) consumed by the Market Data Service andTrader Application.

Trade Report—the Trade Service supplies Trade Report events consumed bythe TPF Adapter 152.

Product Status—the Product Service 144 and Product State Service 146supply Product Status events (State, Price Adjustment, and Update)events consumed by the Trader application, Order Handling Service 220,and TPF Adapter 152.

Trading Session Status—the Trading Session Service 145 supplies TradingSession State events consumed by the Operations Application 140 and HelpDesk application 160.

End of Session Summary—the Trading Session Service supplies End ofTrading Session Status events.

Opening Price—The Broker Service module 230 supplies Opening Priceevents consumed by the Trader Application 136.

Control—the Operations 140 and Help Desk 160 applications supply Controlevents, possibly through the System Management component, consumed byBusiness Services 132 and External Integration Services 133 components.

Order Status—the Order Handling Service 220 (Order) supplies FillReport, Cancel Report, Updated Order, New Order, and Order Accepted byBook events consumed by the Order Status Service 148, and TPF Adapter152.

Quote Status—the MM Quote Service 240 (Quote) supply Fill Report, andDelete Report events consumed by the Quote Status Service 149.

In accordance with a preferred embodiment, there are four major tiers ofthe application software. The business services 132 handle all the SBTorder matching, execution and reporting functionality. It provides therepository for all SBT information data. The application services 210handle the application presentation and act as the application front endto the business services. Different views of the business services 132and collaboration of business objects are grouped together and arepresented to the user based on logon authentication and authorizationlevel. The two tiers communicate to each other by two supported tiers:the infrastructure services 134 and external integration services 133.The infrastructure services 134 provide a seamless integration betweenthe application services 210 and business services 132. The externalintegration services 133 provide the access to the external system.

With reference to FIG. 3, a sequence diagram 200 for a preferredembodiment of the automated exchange system 100 is shown. The system 100includes a client application server 210, an order handling servicemodule 220, a broker service module 230, a quote service module 240, auser service module 260, and quote objects 250 and 252. The servicemodules 220, 230, 240, 260 and objects 250, 252 are preferably softwaremodules running on clusters 102, or on one or more interconnectedcomputers. The software modules are preferably written in anobject-oriented programming language and are compiled to run on theclustered computers 102. Preferably, the software utilizes the C++language, the Java programming language, or other object-orientedlanguage. Alternatively, any suitable software language may be used toimplement the system, as will be understood by one of ordinary skill inthe art. The modules also interact with a database program used forstoring data and other system and user information. In the preferredembodiment an Oracle database system is used.

The client application server 210, as discussed above, runs on clientservers 110, 112, and provides an interface to one or more clients. Theclient server 110, 112 may include one or more application modules,depending upon the intended users of the servers 110, 112. For example,the client servers 110, 112 preferably include at least one of amarket-maker application, a trader application, a back-officeapplication, or a member interface. The client servers 110, 112 alsopreferably utilize a user authentication and role-based security modelto control access to the various application modules.

The client server 110, 112 may also include modules such as a help deskapplication, an operations application, and a Clearing Firm Broker (CFB)module. The CFB module may be configured to allow a Clearing Firm to setmaximum volume limits on a per-class basis. The Help Desk module ispreferably enabled for use on client servers that provide connectivityto exchange management personnel. The Help Desk provides a utility toforce a user to logout of the system.

The order handling service 220 forwards orders to the appropriate brokerservice module 230 that handles the class of options to which theindividual orders relate. If the broker service module 230 cannotexecute the order immediately, it routes it to the order book servicemodule, which maintains the current state of all pending orders andquotes. The order handling service module 220 receives order informationfrom various sources, including brokers, traders, market-makers, etc.The orders may enter the system from a client application server 210 orthrough an alternative interface such as TFP adapter 152, which is aconnection that allows a pre-existing automated order handling systemsuch as TPF system 156, to access the present system.

The broker service module 230 is responsible for executing various typesof orders, including limit, market, all or none, fill or kill, immediateor cancel, stop, stop limit, and spread orders. Preferably, there arenumerous broker service modules 230 running on the exchange server 104,or on the interconnected computers in the cluster 102, where each brokerservice module 230 handles trades for a subset of products offered bythe exchange. For example, there is preferably a broker service module230 for each class of option contracts. The broker service module 230thus matches incoming orders to other orders or to quotes supplied bymarket-makers to complete a trade, indicated by line 282 in FIG. 3.

The broker service module 230 also receives quotes from the quoteservice 240, discussed below. The broker service module 230 attempts toexecute a trade 282 by matching incoming quotes to orders or to otherquotes stored by the order book service module 142 in the order book.Note that for purposes of trade execution 282, quotes are treated by theexchange system 100 as if they were orders. Thus, when the brokerservice module 230 receives a quote that it cannot match to an existingorder or quote, it sends the quote to the order book for storage withother unfilled quotes and orders. Preferably, quotes differ from regularorders in that a quote may be two sided, having a bid and an offerprice, and that each market-maker may only have one quote per product inthe system.

To facilitate the order matching process of trade execution 282, thebroker service module 230 has direct access to orders stored in theorder book by the order book service module 142. Preferably, when theincoming order is matched to an existing quote supplied by the quoteservice module 240, the broker service module 230 provides the quoteservice module 240 with details of the trade.

The quote service module 240 manages the quotes supplied bymarket-makers via client application service module 210. The quoteservice module 240 submits the quotes to the broker service module 230for execution. The quote service module 240 ensures that each individualmarket-maker has only one quote per product in the system at any giventime. When a market-maker enters a new quote on a product for which healready has an outstanding quote, the quote service module preferablydetermines whether there is already an existing quote in the system forthat market-maker and, if so, informs the broker service module 230 thatthe pre-existing quote is to be cancelled. The quote service module 240submits the new quote to the broker service module 230 only after it hasreceived acknowledgement from the broker service module 230 that thepre-existing quote has been cancelled.

The broker service module 230 issues fill reports to notify variousother modules, and ultimately the trading entities, that the trade wasexecuted. Upon notification of a fill 284 from the broker service module230 (or the order book module), the quote service module 240 informs thequote object 250. In turn, the market-maker is notified of the fill viathe exchange's reporting system. The quote service module 240 alsocancels or updates a market-maker quote upon receiving a request fromthe originating market-maker by submitting the request to the brokerservice 230. The quote service module performs this by first informingbroker service module 230 that the pre-existing quote has beencancelled. The broker service module 230 then removes the quote from theorder book and confirms to the quote service 240 that the quote has beencancelled. The quote service 240 then submits the new quote (if oneexists) to the broker service module 230.

With respect to FIG. 3, a preferred sequence of events and messages willbe described. Market-Makers log into a client application server module210 and access the user service module 260. The market-makercommunicates with the user service module 260 through a terminal, suchas a workstation or wireless handheld unit. As shown by line 270,trading parameters, or quote parameters, are sent to the user servicemodule 260. Upon initialization of the quote service, or upon login of anew market-maker, various trading parameters are provided to the quoteservice module 240 as shown by line 271. The trading parameters mayinclude a risk threshold, a quote regeneration indicator, a quoteregeneration increment, a quote modification indicator, and a quotemodification increment. The parameters may include numerous sets ofthresholds, indicators, and increments, preferably one such set for eachclass for which the market-maker is providing quotes.

The quote service module 240 receives quotes from market-makers as shownby line 272, and provides these quotes to the quote objects 250, 252, asshown by update lines 273, 274, and to the broker service module 230 asshown by line 276. As mentioned above, the quote service module 240 willnot forward updated quotes (as opposed to new quotes) to the brokerservice module 230 before first canceling old quotes.

Orders received by the client application server 210 are routed to theorder handling service 220 as shown by line 278. The order is thenforwarded to the appropriate broker service 230 as shown by line 280.The broker service module 230 attempts to execute every order or quotereceived with the best order (or quote) in the book as shown by line282. When a trade is executed, a fill report is issued to the quoteservice module 240 as shown by line 284. The quote service module 240then analyzes the trade and determines whether the market-maker's riskthreshold has been exceeded, as shown by line 286. The threshold testwill be described in further detail below. A fill report is sent to thequote object 250 as shown by line 288. The quote object 250 then informsmarket-maker of the fill through the use of a trade report servicemodule (not shown).

In addition, at steps 286 and 287, the quote service module may modifyquotes in response to the trade in accordance with the market-maker'strading parameters, as discussed below. The quote service module thenreports the new quotes to the broker service module 230 as shown by line290. The broker service 230 acknowledges the quote updates as shown byline 292. If the broker service 230 has already processed additionaltrades against the original quote, then the broker service module 230would respond with a “too late to cancel” message. Once the updateacknowledge has been received, the quote service module 240 updates thequote objects 250, 252, as shown by lines 294, 296. The quote objectsthen inform the market-maker that its quotes have been updated.

Risk Measurements and Risk Thresholds

In a preferred embodiment of the automated trading system 100 havingintegrated order modification and quote risk monitoring, the aggregaterisk of a market-maker's recent trades is calculated after each trade.The measurement preferably includes either calculating an equivalentstock position, i.e., a net delta (by, for example, summing delta valuesfor all contracts traded by the market-maker associated with the optionseries in the class), or calculating a net gamma, theta, or vega.

In particular, the aggregate risk measurement is preferably the netdelta of all the trades for a specific market-maker or a designatedgroup of market-makers in a given class in a given period of time. Thequotes in a given class submitted by a market-maker (or a group ofmarket-makers) are referred to herein as a quote group. The rules fordelta calculations are as listed below:

Calls (delta value Δ is positive)

-   -   Market-maker selling    -   Market-maker position will be Negative Delta    -   Market-maker buying    -   Market-maker position will be Positive Delta        Puts (delta value Δ is negative)    -   Market-maker selling    -   Market-maker position will be Positive Delta    -   Market-maker buying    -   Market-maker position will be Negative Delta

The aggregate risk net delta is defined as:

$\begin{matrix}{{\Delta_{NET} = {\sum\limits_{i}\;{S_{i} \cdot \Delta_{i} \cdot U_{i} \cdot K_{i}}}},} & (1)\end{matrix}$which is the summation for i trades of the product of S, the sign of thetrade, where S is positive when a market-maker buys and negative when amarket-maker sells, Δ (delta), which is rate of change of the price ofthe individual series with respect to the stock, and ranges from −1.0 to0 for puts and 0 to 1.0 for calls, U, which is the unit of trade, i.e.the number of shares, and K, the number of contracts traded by themarket-maker.

The aggregate risk measurement is preferably based on the net deltaΔ_(NET) for the entire class of options, which is the sum of all thedeltas for a given market-maker's trades in all series of a class. Thedelta contribution for each trade is calculated every time a tradeoccurs for any series in the class. The aggregate risk is thencalculated by summing delta contributions from only the most recenttrades. The values for the theoretical deltas Δ_(i) are preferablyobtained by an autoquote system (not shown) associated with the exchangesystem 100, and more particularly with the business services package132.

Autoquote systems provide pricing information, and specificallytheoretical delta values Δ_(i), using well-known algorithms that utilizestandard parameters, as is understood to those of skill in the art. Mostof the parameters associated with calculating an individual series deltavalue are objective data, such as the date, strike price, the price ofthe underlying security, etc. Other autoquote parameters have acceptabledefault values that may be used, such as using the broker loan rate forthe interest rate, etc. One parameter that may be more subjective amongindividual market-makers is the volatility parameter. Thus, the system100 may be designed such that each quote submitted by a market-makerincludes a volatility field to be used by the system in determining theindividual theoretical delta value Δ_(i). The theoretical delta valueΔ_(i) may then be calculated either as part of the threshold test, ormay be periodically updated at a rate sufficient to provide a fairlyaccurate delta value Δ_(i). In this way, the system 100 provides themarket-maker with further control over the quote risk monitoring system.

Because the exchange quote modification service is intended to addressincreased risks associated with a rapid sequence of trades, older tradesneed not be included because the market-maker has had an opportunity tomanually intervene and modify his quotes. Thus, the aggregate riskmeasurement may be based on the last N trades, where N is a tradingparameter specified by the market-maker, or may be based on tradesoccurring within a specific time frame. The duration of the time framemay be specified by the market-maker by providing a time windowparameter t_(K), which is included as a trading parameter.Alternatively, a default value for t_(K) may be used.

Alternatively, the risk threshold and risk measurement may include anaggregate gamma measurement. Gamma is known to those of skill in the artto be the rate of change of the delta parameter with respect to the rateof change of the underlying security, such as the stock. An aggregategamma measurement provides an indication of the rate at which anaggregate delta measurement will change. Net gamma values are negativewhen a market-maker is a net seller of contracts, and positive when amarket-maker is a net buyer of contracts. As a further alternative,either theta, which is the rate at which option prices change over time,or vega, which is the change in an option contract that results from achange in its volatility, may be included.

The market-maker may provide a single threshold Δ_(NETMAX) such that ifthe absolute value of the aggregate risk exceeds the threshold, then thequotes are modified according to the rules set forth below. Themarket-maker may also provide positive and negative thresholds Δ^(Δ)_(NETMAX) and Δ⁻ _(NETMAX) to accommodate a market-maker's pre-existingrisk bias.

In an alternative preferred embodiment, the market-maker's risk isdetermined by calculating the net contract volume traded within aspecified time. The net contract volume K_(NET) may be calculated byusing equation (1) above, with the exception that the delta value isreplaced by the sign of Δ, or ±1, where calls are positive 1, and putsare negative 1:

$\begin{matrix}{{K_{NET} = {\sum\limits_{i}\;{S_{i} \cdot {{sign}\left( \Delta_{i} \right)} \cdot U_{i} \cdot K_{i}}}},{{for}\mspace{14mu}{each}\mspace{14mu}{trade}},{i.}} & (2)\end{matrix}$

The result is that the volume of each trade is treated as a positive ornegative value, depending upon the nature of the trade-selling calls andbuying puts have negative contributions, and buying calls and sellingputs have positive contributions. The sum of the trades is thencalculated to provide a net difference between the number of short callsplus long puts and long calls plus short puts. Thus, the market-makersmay specify a threshold in terms of a maximum net contract volumeoffset, K_(NETMAX) (or positive and negative thresholds K⁺ _(NETMAX) andK⁻ _(NETMAX) to accommodate a market-maker's pre-existing risk bias). Asstated above, the system may be configured to also allow themarket-makers to specify a time window parameter t_(K) that specifieswhich trades should be included in the risk calculation. Thus, only thecontracts K that have been executed within the previous t seconds willbe included in equation 2. Alternatively, the system may be configuredto specify i, the number of previous trades to include in the riskcalculation.

In still further embodiments, the aggregate risk measurement may besimplified by calculating the total number of put or call contracts (ordeltas) that have been sold or bought within a given time frame orwithin that last N trades. Thus, for example, when a market-maker hasjust sold a put, the quote service module 240 may calculate the totalnumber of puts sold (or the delta due to all the puts sold) within thegiven trading window and compare it to a threshold. If the next trade isa call purchase, then the system would calculate the contracts or deltasfor the calls purchased. Thus, if any of the four aggregate volumequantities (buying calls, selling calls, buying puts, selling puts)exceeds a threshold (within a certain time period, or certain number oftrades), the quote modification module 340 modifies the quotesappropriately. Alternatively, the quote service module 240 may calculatethe total calls bought plus puts sold, and the total calls sold plusputs bought, and notify the quote modification module 340 if either ofthese aggregate values exceeds the threshold. As a further alternative,the quote service module may use a weighting scheme to calculateaggregate values described above. Specifically, in-the-money options(options with intrinsic value) may be weighted more heavily thanat-the-money or out-of-the-money options. In one preferred method, thein-the-money options are weighted with a factor of two, at-the-moneyoptions are weighted with a factor of one, and out-of-the-money optionsare weighted by a factor of one half. These simplified risk measurementand threshold tests perform adequately due to the nature of tradingactivities that typically result in large risk exposure.

It should also be noted that the market-makers may be grouped togetherfor purposes of risk exposure analysis. That is, the total risk may becalculated based on the trades of one or more market-makers. Themarket-makers provide a group identification parameter(s) indicatingwhich other market-makers' trades should be included in the riskcalculation. In this manner, market-makers acting in concert on behalfof a single organization may coordinate their quote modification.

Automatic Quote Modification

The quote service module 240 of the exchange system 100 includes a quotemodification service module 340. The quote modification service module340 may be implemented as part of the quote service module 240, or maybe a separate service module. It may also take the form of a separatequote factory module for generating new instantiations of quote objects.The quote modification service module 340 performs quote modification bypreferably automatically revising, canceling, or regenerating quotes.The quote modification service module 340 resides on the exchange systemcomputer 104, 106, or computer cluster 102. The quotes are modified bythe exchange system in an automatic manner that does not require furtherinput from the market-maker in the form of quote cancellation requestsand submission of new quotes by the market-maker or his computer. Inthis way, the exchange system performs quote modification immediatelyand without the transmission delays inherent in communication systemsand without delays associated with processing queued cancellationrequests received from a remote location.

If the quote service module 240 determines that the threshold(s) havebeen exceeded, the quote service module 240 determines revised quotesand forwards them to the broker service module 230 and the quote objects250, 252. The revised quotes can take numerous forms. In a firstembodiment, the quote service module 240 revises quotes by canceling alloutstanding quotes in the class, thereby preventing any further tradesfrom executing and giving the market-maker time to provide revisedquotes. In this embodiment, the quote service module 240 sends quoteupdate messages 290 in the form of cancellation messages to the brokerservice module 230. The broker service 230 then removes those quotesfrom the electronic book. Because the threshold test is performed by theexchange system 100 after each trade, the cancellation messages aretherefore preferably processed before any further trades can beexecuted. This is possible because the cancellation requests are notsent from a remote node on a wide area network, such as a market-maker'scomputing platform, but are generated by the exchange system 100. Thisprovides the advantage of eliminating a cancellation message queue, aswould be used when sending cancellation requests from a remote node,thereby improving quote update times and providing risk management.

In a second embodiment, the quote service module 240 revises quotes byreducing the quantity associated with the existing quotes in the classthereby reducing the amounts of potential further trades and reducingthe market-maker's exposure to more risk. The market-maker may specifythe amount of the volume decrease by way of an increment value. In thisembodiment, the quote service module 240 sends quote updates 290 byfirst sending quote cancellation messages to the broker service module230, and after acknowledgment, sending the revised quotes to the brokerservice module 230 for execution or booking. Again, because thethreshold test is performed by the exchange system 100 after each trade,the cancellation messages are therefore preferably processed before anyfurther trades can be executed. As above, this is possible because thecancellation requests are not sent from a remote node on a wide areanetwork, such as a market-maker's computing platform, but are generatedby the exchange system 100.

In a third embodiment, the quote service module 240 revises quotes bydecreasing the bid and offer values of some quotes and increasing othersin an attempt to cancel some of the risk already assumed by themarket-maker. The quote service 240 does this by automatically adjustingquotes to favor trades that will tend to provide offsetting risk.Specifically, if the threshold (K_(NETMAX) or Δ_(NETMAX)) has beenexceeded by a high positive-valued net delta (or K), then the net delta(or K) may be offset by trades having a negative delta (or K). As setforth above, those trades would include selling calls and buying puts.Similarly, if the threshold has been exceeded by a high negative-valuednet delta (or K), then the aggregate risk may be offset by trades havinga positive delta (or K), or by selling puts and buying calls. Of course,to produce the desired trades, the lowering of offer values of quoteswill tend to result in more selling activity by the market-maker, andthe raising of bid values will result in more buying activity by themarket-maker. In this embodiment, the modification increment isspecified by an increment value. As in the previous embodiment, thequote service module 240 sends quote updates 290 by sending quotecancellation messages to the broker service module 230, and afteracknowledgment, sending the revised quotes to the broker service module230 for execution or booking. Again the automated risk monitoring systemand quote modification service of system 100 provides advantages in thatthe market-maker need not cancel previous quotes and submit new quoteswhile still being exposed to the possibility of further trades beingexecuted.

The quote service 240 may also modify quotes by regenerating thejust-filled quote. This may be performed even if the market-maker's riskthreshold has not been exceeded. The market-maker is able to specifyquote regeneration parameters via client application server 210 that arestored in the user service module 260. The parameters specify whichproducts are enabled for quote regeneration, and the extent to which thequotes are to be regenerated. The market-maker may therefore specify, ona product-by-product basis, how many times the quotes are to beregenerated after each quote has been filled. This is referred to hereinas the regeneration number parameter. The market-maker may also specifywhether the regenerated quotes are to have the same bid and offervalues, or are to be backed-off from the previous trade. This parameteris referred to herein as the regeneration increment. That is, for atwo-sided quote, if the market-maker has just sold a quantity ofcontracts at his offer price, the regenerated quote may have a higheroffer value. Preferably the bid value is also raised accordingly tomaintain a desired or required spread in bid and offer quotes. If, onthe other hand, the market-maker has just bought a quantity of contractsat his bid price, the regenerated quote may have a lower bid value. Themarket-maker also has the option of specifying on a per-class basis thevalues of the regeneration number parameter and the regenerationincrement parameter. The quote regeneration is preferably not performedif the market-maker risk threshold has been exceeded, unless themarket-maker has specifically selected quote revision in the event therisk threshold has been exceeded.

With reference to FIG. 4, the method of quote modification 300 will bedescribed. Upon execution of a trade at step 310, the quote servicemodule 240 at step 320 checks to see whether the individualmarket-maker's risk threshold has been exceeded. As mentioned above, therisk measurement and threshold test may be performed using a variety ofmethods, and certain market-makers' trading activities may be combinedfor the purposes of risk exposure. If the threshold has not beenexceeded, then at step 330 the quote service module 240 preferablychecks to see whether the market-maker whose quote has been executed hasindicated the desire to have his quotes regenerated. If not, then theprocess has completed. In the event that the result of either inquiry320, 330 is affirmative, then the quote service 240 modifies the quoteswith the quote modification module 340 as described above.

Quote modification module 340 includes quote regeneration module 350 andcancel or revise quote module 360. As mentioned above, the quotemodification module 340 may be integral to quote service module 240, ormay be included in a quote factory module, or may be a separate servicemodule. The quotes are regenerated, cancelled, or revised, for exampleas described above, and submitted as shown in step 370 to the brokerservice module 230 for execution.

Preferred embodiments of the present invention have been describedherein. It is to be understood, of course, that changes andmodifications may be made in the embodiments without departing from thetrue scope of the present invention, as defined by the appended claims.The present embodiment preferably includes logic to implement thedescribed methods in software modules as a set of computer executablesoftware instructions. A Central Processing Unit (“CPU”), ormicroprocessor, implements the logic that controls the operation of thetransceiver. The microprocessor executes software that can be programmedby those of skill in the art to provide the described functionality.

The software can be represented as a sequence of binary bits maintainedon a computer readable medium including magnetic disks, optical disks,and any other volatile or (e.g., Random Access memory (“RAM”))non-volatile firmware (e.g., Read Only Memory (“ROM”)) storage systemreadable by the CPU. The memory locations where data bits are maintainedalso include physical locations that have particular electrical,magnetic, optical, or organic properties corresponding to the storeddata bits. The software instructions are executed as data bits by theCPU with a memory system causing a transformation of the electricalsignal representation, and the maintenance of data bits at memorylocations in the memory system to thereby reconfigure or otherwise alterthe unit's operation. The executable software code may implement, forexample, the methods as described above.

It should be understood that the programs, processes, methods andapparatus described herein are not related or limited to any particulartype of computer or network apparatus (hardware or software), unlessindicated otherwise. Various types of general purpose or specializedcomputer apparatus or computing device may be used with or performoperations in accordance with the teachings described herein.

It should be understood that a hardware embodiment may take a variety ofdifferent forms. The hardware may be implemented as an integratedcircuit with custom gate arrays or an application specific integratedcircuit (“ASIC”). Of the course, the embodiment may also be implementedwith discrete hardware components and circuitry. In particular, it isunderstood that the logic structures and method steps described hereinmay be implemented in dedicated hardware such as an ASIC, or as programinstructions carried out by a microprocessor or other computing device.

The claims should not be read as limited to the described order ofelements unless stated to that effect. In addition, use of the term“means” in any claim is intended to invoke 35 U.S.C. §112, paragraph 6,and any claim without the word “means” is not so intended. Therefore,all embodiments that come within the scope and spirit of the followingclaims and equivalents thereto are claimed as the invention.

1. A method of modifying quotes in an automated exchange trading systemcomprising the steps of: receiving orders and quotes, wherein specifiedones of said quotes belong to a quote group, and wherein said specifiedones of said quotes have associated trading parameters comprising a riskthreshold; generating a trade by matching said received orders andquotes to previously received orders and quotes; storing each of saidorders and quotes when a trade is not generated; determining whether aquote having associated trading parameters has been filled as a resultof the generated trade, and if so, determining a risk level and anaggregate risk level associated with said trade; comparing saidaggregate risk level with said risk threshold; and, automaticallymodifying at least one of the remaining said specified ones of saidquotes in the quote group if said threshold is exceeded.
 2. The methodof claim 1 wherein the quotes are stored in a quote data structurecontaining a plurality of quotes fields and at least one risk thresholdfield.
 3. The method of claim 2, wherein the plurality of quote fieldscomprises a bid quote field and an offer quote field.
 4. The method ofclaim 2, wherein the data structure further comprises a group indicatorfield.
 5. The method of claim 2, wherein the data structure furthercomprises a quote modification increment field.
 6. The method of claim2, wherein the data structure further comprises a quote regenerationincrement field.
 7. The method of claim 2, wherein the data structurefurther comprises an owner field.
 8. A method of modifying quotes in anautomated exchange trading system that receives orders and quotes fromremote computers, matches the orders and quotes to generate trades, andstores orders and quotes that are unmatched, comprising the steps of:receiving trading parameters comprising a risk threshold; associatingsaid trading parameters with specified ones of received quotes;determining whether a quote having associated trading parameters hasbeen filled as a result of a generated trade, and if so, determining arisk level and an aggregate risk level associated with said trade;comparing said aggregate risk level with said risk threshold; and,automatically modifying at least one of the specified ones of receivedquotes if said threshold is exceeded.
 9. The method of claim 8 whereinthe step of determining a risk level comprises calculating a delta valuefor the generated trade.
 10. The method of claim 8 wherein the step ofdetermining a risk level comprises calculating a trading volume for thegenerated trade.
 11. The method of claim 8 wherein the step ofdetermining an aggregate risk level comprises determining a net delta.12. The method of claim 8 wherein the trading parameters furthercomprise a time duration, and wherein the step of determining anaggregate risk level comprises summing the deltas from trades involvingat least a subset of quotes contained in said quote group that wereexecuted within the time duration.
 13. The method of claim 8 wherein thetrading parameters further comprise an integer N, and wherein the stepof determining an aggregate risk level comprises summing the deltas fromthe most recent N trades involving at least a subset of quotes containedin said quote group.
 14. The method of claim 8 wherein the step ofdetermining an aggregate risk level comprises determining a net contractvolume.
 15. The method of claim 8 wherein the step of determining anaggregate risk level comprises determining a weighted sum of contractvolumes.
 16. The method of claim 8 wherein the step of determining anaggregate risk level comprises determining an aggregate volume quantity.17. The method of claim 8 wherein the step of automatically modifying atleast one of the specified ones of said received quotes comprisescanceling all said specified ones of said received quotes.
 18. Themethod of claim 8 wherein the step of automatically modifying at leastone of the specified ones of said received quotes comprises reducing thequantity associated with the specified ones of received quotes.
 19. Themethod of claim 8 wherein the step of automatically modifying at leastone of the specified ones of said quotes comprises revising at least oneof the bid and offer values of each of the specified ones of receivedquotes.
 20. The method of claim 8 wherein the trading parameterscomprise a positive risk threshold and a negative risk threshold. 21.The method of claim 20 wherein the step of comparing the aggregate risklevel with the risk threshold comprises comparing the aggregate risklevel to the positive risk threshold if the aggregate risk level ispositive, and comparing the aggregate risk level to the negative riskthreshold if the aggregate risk level is negative.
 22. The method ofclaim 8 wherein the step of comparing the aggregate risk level with therisk threshold comprises comparing the absolute value of the aggregaterisk level to the risk threshold.
 23. The method of claim 8 wherein eachof the specified ones of received quotes are associated with one of afirst subgroup and second subgroup, and wherein the step ofautomatically modifying at least one of the specified ones of receivedquotes in the quote group comprises reducing the offer values of thequotes in the first subgroup and raising the bid values of the quotes inthe second subgroup.
 24. The method of claim 23 wherein the firstsubgroup comprises quotes on call series options and the second subgroupcomprises quotes on put series options, and wherein the aggregate riskis positive.
 25. The method of claim 23 wherein the first subgroupcomprises quotes on put series options and the second subgroup comprisesquotes on call series options, and wherein the aggregate risk isnegative.
 26. The method of claim 23 where the amount of said reducingand raising is determined in response to a modification incrementparameter.
 27. The method of claim 8 further comprising the step ofautomatically modifying a quote comprises regenerating a quote havingassociated trading parameters that has been filled as a result of thegenerated trade.
 28. The method of claim 27 wherein the step ofregenerating a quote is performed utilizing a regeneration increment.